Display device

ABSTRACT

A display device includes: a substrate; a plurality of pixels provided in a pixel region of the substrate; a scan line and a data line, connected to each of the plurality of pixels; a first transistor connected to the scan line and the data line and a second transistor connected to the first transistor; a light emitting element connected to the transistor; a first blocking layer disposed between the substrate and the first transistor, the first blocking layer being electrically connected to the first transistor; and a second blocking layer disposed between the substrate and the second transistor, the second blocking layer being electrically connected to the second transistor, wherein the first blocking layer is connected to a gate electrode of the first transistor, and the second blocking layer is connected to any one of source and drain electrodes of the second transistor.

RELATED APPLICATIONS

The present application claims priority to Korean Patent Application No.10-2016-0155155 filed on Nov. 21, 2016, in the Korean IntellectualProperty Office, the entire disclosure of which is incorporated byreference herein.

BACKGROUND 1. Field

An aspect of the present disclosure relates to a display device.

2. Description of the Related Art

As interest in information displays and demand for portable informationmedia increase, research and commercialization has focused on displaydevices.

Particularly, recently, as the requirement for high resolution displaydevice increases, the size of a pixel has decreased. On the other hand,the structure of a circuit included in the pixel has been graduallycomplicated.

SUMMARY

Embodiments provide a display device which facilitates theimplementation of high resolution.

According to an aspect of the present disclosure, there is provided adisplay device including: a substrate including a pixel region and aperipheral region; a plurality of pixels provided in the pixel region ofthe substrate; a scan line and a data line, connected to each of theplurality of pixels; a transistor provided in the pixel region, thetransistor including a first transistor connected to the scan line andthe data line and a second transistor connected to the first transistor;a light emitting element connected to the transistor; a first blockinglayer disposed between the substrate and the first transistor, the firstblocking layer being electrically connected to the first transistor; anda second blocking layer disposed between the substrate and the secondtransistor, the second blocking layer being electrically connected tothe second transistor, wherein the first blocking layer is connected toa gate electrode of the first transistor, and the second blocking layeris connected to any one of source and drain electrodes of the secondtransistor.

When viewed on a plane, the first blocking layer may overlap with aportion of the first transistor, and the second blocking layer mayoverlap with a portion of the second transistor.

The first blocking layer and the second blocking layer may be providedon the same layer.

The second transistor may include: an active pattern disposed on thesubstrate; a gate electrode disposed on the active pattern; and sourceand drain electrodes, each connected to the active pattern. The sourceelectrode may be connected to the second blocking layer.

The second blocking layer may be a light blocking layer that blockslight incident through one surface of the substrate, on which the activepattern of the second transistor is not provided.

The display device may include: a buffer layer disposed between thesecond blocking layer and the active pattern; and a gate insulatinglayer, a first insulating layer, and a second insulating layer,sequentially disposed on the buffer layer.

The display device may include: a lower electrode disposed on the gateinsulating layer; and an upper electrode disposed on the firstinsulating layer. The lower electrode and the upper electrode mayconstitute a storage capacitor with the first insulating layerinterposed therebetween.

The lower electrode may be integrally provided with the gate electrodeof the second transistor.

The display device may include: a lower electrode disposed between thesubstrate and the buffer layer; and an upper electrode disposed on thegate insulating layer. The lower electrode and the upper electrode mayconstitute a storage capacitor with the buffer layer and the gateinsulating layer interposed therebetween.

The second blocking layer may be integrally provided with the lowerelectrode.

The first transistor may include: an active pattern disposed on thesubstrate; a gate electrode disposed on the active pattern; and sourceand drain electrodes, each connected to the active pattern. The firstblocking layer may be a light blocking layer that blocks light incidentthrough one surface of the substrate, on which the active pattern of thefirst transistor is not provided.

The display device may further include: an emission control linedisposed on the second insulating layer; a third transistor connected tothe emission control line and the second transistor; and a thirdblocking layer connected to the third transistor.

When viewed on a plane, the third blocking layer may overlap with aportion of the third transistor.

The third transistor may include: an active pattern disposed on thesubstrate; a gate electrode disposed on the active pattern; and sourceand drain electrodes, each connected to the active pattern. The gateelectrode may be connected to the third blocking layer.

The third blocking layer may be a light blocking layer that blocks lightincident through one surface of the substrate, on which the activepattern of the third transistor is not provided.

The third blocking layer may be provided on the same layer as the firstand second blocking layers.

The emission control line may be provided on the same layer as the dataline.

According to another aspect of the present disclosure, there is provideda display device including: a first transistor connected to a data lineand a scan line to supply a data signal to a first node; a storagecapacitor having one electrode connected to the first node and the otherelectrode connected to a second node; a light emitting element havingone electrode connected to the second node and the other electrodeconnected to a second power source; a second transistor supplying acurrent corresponding to a voltage applied to the first node from afirst power source to the second power source via the light emittingelement; a third transistor connected to the second transistor and anemission control line; and first to third blocking layers respectivelyprovided under active patterns of the first to third transistors, thefirst to third blocking layers each being connected to a correspondingtransistor, wherein at least one of the first to third blocking layersis connected to a source electrode of the second transistor, and theother of the first to third blocking layers is connected to a gateelectrode of a corresponding transistor.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments will now be described more fully hereinafter withreference to the accompanying drawings; however, they may be embodied indifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the example embodiments to those skilled in the art.

In the drawing figures, dimensions may be exaggerated for clarity ofillustration. It will be understood that when an element is referred toas being “between” two elements, it can be the only element between thetwo elements, or one or more intervening elements may also be present.Like reference numerals refer to like elements throughout.

FIG. 1 is a view illustrating a display device according to anembodiment of the present disclosure.

FIG. 2 is a circuit diagram illustrating an embodiment of a pixel shownin FIG. 1.

FIG. 3 is a driving timing diagram illustrating driving of the pixelshown in FIG. 2.

FIG. 4 is a plan view implementing the pixel of FIG. 2 according to anembodiment of the inventive concept.

FIG. 5 is a plan view illustrating in detail the pixel of FIG. 4.

FIG. 6 is a sectional view taken along line I-I′ of FIG. 5.

FIGS. 7A, 7B, 7C, 7D and 7E are layout diagrams schematicallyillustrating components of the pixel shown in FIG. 5 for each layer.

FIG. 8 is a plan view implementing the pixel of FIG. 2 according toanother embodiment of the inventive concept.

FIG. 9 is a sectional view taken along line II-II′ of FIG. 8.

FIGS. 10A, 10B, 10C and 10D are layout diagrams schematicallyillustrating components of the pixel shown in FIG. 8 for each layer.

DETAILED DESCRIPTION

The present disclosure may apply various changes and different shape,therefore only illustrate in details with particular examples. However,the examples do not limit to certain shapes but apply to all the changeand equivalent material and replacement. The drawings included areillustrated a fashion where the figures are expanded for the betterunderstanding.

Like numbers refer to like elements throughout. In the drawings, thethickness of certain lines, layers, components, elements or features maybe exaggerated for clarity. It will be understood that, although theterms “first”, “second”, etc. may be used herein to describe variouselements, these elements should not be limited by these terms. Theseterms are only used to distinguish one element from another element.Thus, a “first” element discussed below could also be termed a “second”element without departing from the teachings of the present disclosure.As used herein, the singular forms are intended to include the pluralforms as well, unless the context clearly indicates otherwise.

It will be further understood that the terms “includes” and/or“including”, when used in this specification, specify the presence ofstated features, integers, steps, operations, elements, and/orcomponents, but do not preclude the presence and/or addition of one ormore other features, integers, steps, operations, elements, components,and/or groups thereof. Further, an expression that an element such as alayer, region, substrate or plate is placed “on” or “above” anotherelement indicates not only a case where the element is placed “directlyon” or “just above” the other element but also a case where a furtherelement is interposed between the element and the other element. On thecontrary, an expression that an element such as a layer, region,substrate or plate is placed “beneath” or “below” another elementindicates not only a case where the element is placed “directly beneath”or “just below” the other element but also a case where a furtherelement is interposed between the element and the other element.

Hereinafter, exemplary embodiments of the present disclosure will bedescribed in detail with reference to the accompanying drawings.

FIG. 1 is a view illustrating a display device according to anembodiment of the present disclosure.

Referring to FIG. 1, the display device according to the embodiment ofthe present disclosure may include a scan driver 110, a data driver 120,a pixel unit 130 including pixels PXL, and a timing controller 150.

The pixel unit 130 includes pixels PXL disposed in regions defined byscan lines S1 to Sn and data lines D1 to Dm. In FIG. 1, it isillustrated that the pixel unit 130 includes m×n pixels PXL. The pixelsPXL are supplied with a first power source ELVDD and a second powersource ELVSS from the outside. In an embodiment of the presentdisclosure, the second power source ELVSS may be set to a voltage lowerthan that of the first power source ELVDD. The pixels PXL are suppliedwith a data signal, corresponding to a scan signal supplied to the scanlines S1 to Sn. Each of the pixels PXL supplied with the data signalgenerates light with a predetermined luminance while controlling theamount of current flowing from the first power source ELVDD to thesecond power source ELVSS via a light emitting device, corresponding tothe data signal.

Each of the pixels PXL in the pixel unit 130 shown in FIG. 1 may be asub-pixel included in a unit pixel. That is, each of the pixels PXL maybe a sub-pixel that generates light of any one color among red, green,and blue, but the present disclosure is not limited thereto.

The timing controller 150 generates a data driving control signal DCSand a scan driving control signal SCS, corresponding to synchronizationsignals supplied from the outside, for example, a graphic controller.The data driving control signal DCS generated from the timing controller150 is supplied to the data driver 120, and the scan driving controlsignal SCS generated from the timing controller 150 is supplied to thescan driver 110. Also, the timing controller 150 rearranges datasupplied from the outside and supplies the rearranged data Data to thedata driver 120.

The scan driver 110 is supplied with the scan driving control signal SCSfrom the timing controller 150. The scan driver 110 supplied with thescan driving control signal SCS supplies the scan signal to the scanlines S1 to Sn. If the scan signal is supplied to the scan lines S1 toSn, the pixels PXL connected to the scan line are selected.

In addition, the scan driver 110 supplied with the scan driving controlsignal SCS may include an emission control driver (not shown) thatsupplies an operation control signal to emission control lines E1 to En.The operation control signal may be used to control an emission time ofeach pixel PXL and compensate for an initialization voltage and athreshold voltage of the pixel PXL.

The data driver 120 supplies the data signal to the data lines D1 to Dm,corresponding to the data driving control signal DCS. The data signalsupplied to the data lines D1 to Dm is supplied to the selected pixelsPXL by the scan signal. To this end, the data driver 120 may supply thedata signal to the data lines D1 to Dm to be synchronized with the scansignal. The data driver 120 may include a compensator that extractscurrent information of the light emitting device from each pixel PXL.The compensator may extract a current value of the light emitting deviceincluded in each of the pixels PXL during a sensing period in which theoperation control signal is supplied to the emission control lines E1 toEn.

In an embodiment, the display device may be driven in a simultaneousemission manner.

According to the simultaneous emission manner, the period of one frameincludes an addressing period in which a plurality of data signals aretransmitted and programmed to each of the pixels PXL, and an emissionperiod in which light is emitted according to each of the data signalsprogrammed in the respective pixels PXL after the data signals arecompletely programmed to the pixels PXL. In an embodiment, the datasignals are sequentially input, but light may be emitted from the lightemitting devices at the same time after the data signals are completelyinput.

More specifically, in an embodiment, each pixel PXL may be driven,generally including a first period (an initializing step of initializinga driving voltage of the light emitting device in the pixel PXL), asecond period (a threshold voltage compensating step of compensating athreshold voltage of a driving transistor of the light emitting device),a third period (an addressing step of addressing the data signal to eachof a plurality of pixels PXL), and a fourth period (a light emittingstep of allowing the light emitting device of each of a plurality ofpixels PXL to emit light, corresponding to the data signal).

The third period is sequentially performed for each of the scan lines S1to Sn, but the other periods may be simultaneously performed in thepixel unit 130. The first to fourth periods will be described in detaillater with reference to FIGS. 2 and 3.

FIG. 2 is a circuit diagram illustrating an embodiment of the pixelshown in FIG. 1. FIG. 3 is a driving timing diagram illustrating drivingof the pixel shown in FIG. 2. A pixel PXL located on an ith row (i is anatural number smaller than n) and a jth column (j is a natural numbersmaller than m) is illustrated in FIG. 2.

Referring to FIGS. 1 to 3, the pixel PXL according to the embodiment ofthe present disclosure may include a light emitting element OLED, a dataline Dj, a scan line Si, and an emission control line Ei. Also, thepixel PXL may include a pixel circuit connected to each of the data lineDj, the scan line Si, and the emission control line Ei.

An anode electrode of the light emitting element OLED is connected tothe pixel circuit, and a cathode electrode of the light emitting elementOLED is connected to the second power source ELVSS. The light emittingelement OLED generates light with a predetermined luminancecorresponding to the amount of current supplied from the pixel circuitunit. To this end, the second power source ELVSS may be set to a voltagelower than that of the first power source ELVDD during a driving periodof the display device.

The pixel circuit may control the amount of current flowing from thefirst power source ELVDD to the second power source ELVSS via the lightemitting element OLED, corresponding to a data signal Data. To this end,the pixel circuit may include first to third transistors T1 to T3, astorage capacitor Cst, and an auxiliary capacitor Coled.

The first transistor (switching transistor) T1 is disposed between thedata line Dj and a first node N1, and is connected to each of the dataline Dj and a gate electrode of the second transistor T2. The firsttransistor T1 is turned on when a scan signal Scan_1 to Scan_n issupplied to the scan line Si, to allow the data line Dj and the gateelectrode of the second transistor T2 to be electrically connected toeach other. The first transistor T1 may be turned on in response to thescan signal Scan_1 to Scan_n provided through the scan line Si toperform a switching operation of transmitting the data signal Dataprovided from the data line Dj to the gate electrode of the secondtransistor T2. To this end, the first transistor T1 may include a gateelectrode connected to the scan line Si, a drain electrode connected tothe data line Dj, and a source electrode connected to a first node N1.The gate electrode of the first transistor T1 may be connected to afirst blocking layer made of a conductive material. Here, the firstblocking layer may be disposed under the first transistor T1 topartially overlap with the first transistor T1. The first blocking layermay be disposed under the first transistor T1 to completely overlap witha channel region of the first transistor T1.

The second transistor (driving transistor) T2 may be disposed betweenthe power source ELVDD and the second power source ELVSS. The gateelectrode of the second transistor T2 may be connected to the first nodeN1, a source electrode of the second transistor T2 may be connected tothe anode electrode of the light emitting element OLED, and a drainelectrode of the second transistor T2 may be connected to the firstpower source ELVDD via the third transistor. The second transistor T2controls the amount of the current flowing from the first power sourceELVDD to the second power source ELVSS via the light emitting elementOLED, corresponding to a voltage of the first node N1. The sourceelectrode of the second transistor T2 may be connected to a secondblocking layer made of a conductive material. Here, the second blockinglayer may be disposed under the second transistor T2 to partiallyoverlap with the second transistor T2. The second blocking layer may bedisposed under the second transistor T2 to completely overlap with achannel region of the second transistor T2.

The third transistor T3 is disposed between the first power source ELVDDand the second transistor T2, and is connected to each of the firstpower source ELVDD and the second transistor T2. In addition, a gateelectrode of the third transistor T3 is connected to the emissioncontrol line Ei. Turn-on/turn-off of the third transistor T3 may bedetermined by an operation control signal GC applied to the emissioncontrol line Ei. The third transistor T3 may include the gate electrodeconnected to the emission control line Ei, a drain electrode connectedto the first power source ELVDD, and a source electrode connected to thedrain electrode of the second transistor T2. The gate electrode of thethird transistor T3 may be connected to a third blocking layer made of aconductive material. Here, the third blocking layer may be disposedunder the third transistor T3 to partially overlap with the thirdtransistor T3. The third blocking layer may be disposed under the thirdtransistor T3 to completely overlap with a channel region of the thirdtransistor T3.

In FIG. 2, it is illustrated that the first to third transistors T1 toT3 are all implemented as NMOS transistors, but the present disclosureis not limited thereto. For example, the first to third transistors T1to T3 may be implemented as PMOS transistors.

The storage capacitor Cst stores a voltage corresponding to the datasignal Data, and is connected between the first node N1 and a secondnode N2.

The auxiliary capacitor Coled may be connected to use the couplingeffect of the storage capacitor by considering the capacity of aparasitic capacitor, generated by the anode and cathode electrodes ofthe light emitting element OLED.

Each pixel PXL may be driven in the simultaneous emission manner. Inthis case, one frame may be implemented, including a first period (aninitialization period, hereinafter referred to as “a”), a second period(a threshold voltage compensation period, hereinafter referred to as“b”), a third period (an addressing period, hereinafter referred to as“c”), and a fourth period (a light emitting period, hereinafter referredto as “d”).

The first period a is a step of initializing a voltage applied to thelight emitting element OLED. The first period a may be a period inwhich, when the cathode electrode of the light emitting element OLED isfixed to a certain voltage, a voltage applied to the anode electrode ofthe light emitting element OLED is set to a predetermined voltage, forexample, 0V. In an embodiment, the voltage applied to the cathodeelectrode of the light emitting element OLED may be set to a voltagehigher than 0V so as to block leakage current generated during the firstperiod a.

During the first period a, the first power source ELVDD may be appliedat a low level (e.g., 0V), the scan signal Scan_1 to Scan_n may beapplied at a high level to a corresponding scan line, the operationcontrol signal GC may be applied at a high level, and the data signalData may be applied at a low level. In this case, the data signal Datamay be applied at a predetermined high level so as to rapidly initializethe voltage applied to the anode electrode of the light emitting elementOLED. In addition, during the first period a, the second power sourceELVSS may be applied at a predetermined high level.

During the first period a, electric charges accumulated in the anodeelectrode of the light emitting element OLED is quickly discharged bythe voltage of 0V, and the voltage of the light emitting element OLEDmay also be quickly initialized.

The second period b is a step of compensating for a threshold voltage ofthe second transistor T2. During the second period b, the thresholdvoltage of the second transistor T2 is stored in the storage capacitorCst. After that, the threshold voltage of the second transistor T2 canremove a failure caused by a threshold voltage variation of the secondtransistor T2 when the data signal Data is charged in each pixel PXL.

During the second period b, the first power source ELVDD may be appliedat a high level, each of the scan signal Scan_1 to Scan_n and theoperation control signal GC may be applied at a high level, and the datasignal Data may be applied at the same level as the first period a. Inthis case, the data signal Data may be applied at a predetermined highlevel at which the second transistor T2 can be turned on.

Each of the signals applied to each pixel PXL during the second periodb, i.e., the first power source ELVDD, the scan signal Scan, theoperation control signal GC, the data signal Data, and the second powersource ELVSS may be simultaneously applied with a voltage value of a setlevel to a plurality of pixels PXL. As the signal is applied asdescribed above, during the second period b, the first to thirdtransistors T1 to T3 may be turned on, and a voltage corresponding tothe threshold voltage of the second transistor T2 may be charged in thestorage capacitor Cst.

The third period c is a step of sequentially applying the scan signalScan_1 to Scan_n to the scan lines S1 to Sn connected to the pixels PXLand applying the data signal Data to a data line (D1 to Dm of FIG. 1) ofeach pixel, corresponding to the scan signal Scan_1 to Scan_n. In thiscase, the second power source ELVSS may be applied at the same level asthe first period a and the second period b.

During the third period c, the operation control signal GC may beapplied at a low level. As the operation control signal GC is applied atthe low level, the third transistor T3 is turned off, and accordingly,the first power source ELVDD may be provided as a voltage of any levelduring the third period c. In an embodiment, the first power sourceELVDD may be applied at a high level during the third period c.

In the pixel PXL according to the embodiment of the present disclosure,the scan signal Scan_1 to Scan_n of a high level is applied during thethird period c, so that the first transistor T1 is turned on.Accordingly, the data signal Data having a predetermined level value isapplied to the first node N1 via the drain and source electrodes of thefirst transistor T1. In this case, voltages at both ends of the storagecapacitor Cst may be changed depending on a change in voltage of thedata signal Data. Also, in the pixel PXL according to the embodiment ofthe present disclosure, the third transistor T3 is turned off during thethird period c, so that any current path is not formed between the lightemitting element OLED and the first power source ELVDD. Therefore, thelight emitting element OLED does not emit light during the third periodc.

The fourth period d is a light emitting period in which the lightemitting element OLED emits light corresponding to the data signal Datainput during the third period c.

During the fourth period d, the first power source ELVDD may be appliedat a high level, the scan signal Scan_1 to Scan_n may be applied at alow level, and the operation control signal GC may be applied at a highlevel. In this case, the data signal Data may be applied at apredetermined level at which any leakage current is not generated in thefirst transistor T1.

Each of the signals applied to each pixel PXL during the fourth periodd, i.e., the first power source ELVDD, the scan signal Scan, theoperation control signal GC, and the data signal Data may besimultaneously applied as a voltage value of a set level. As the signalis applied as described above, during the fourth period d, the firsttransistor T1 may be turned off, and the second and third transistors T2and T3 may be turned on. As the second and third transistors T2 and T3are turned on, a current path is formed between the first power sourceELVDD and the light emitting element OLED, so that a currentcorresponding to the voltage between the gate and source electrodes ofthe second transistor T2 is applied to the light emitting element OLED.Therefore, the light emitting element OLED emits light.

FIG. 4 is a plan view implementing the pixel of FIG. 2 according to anembodiment of the inventive concept. FIG. 5 is a plan view illustratingin detail the pixel of FIG. 4. FIG. 6 is a sectional view taken alongline I-I′ of FIG. 5. In FIGS. 4 to 6, for convenience of description, inlines provided to one pixel, a scan line to which a scan signal isapplied is designated as a “scan line SL,” an emission control line towhich an operation control signal is applied is designated as an“emission control line EL,” a data line to which a data signal isapplied is designated as a “data line DL1,” and a power line to whichthe first power source ELVDD is applied is designated as a “power linePL.”

Referring to FIGS. 2 to 6, the display device according to theembodiment of the present disclosure includes a substrate SUB, signallines and pixels PXL.

The substrate SUB may include a pixel region and a peripheral regionprovided at at least one side of the pixel region. The pixel region is aregion in which the pixels PXL are provided to display an image, and theperipheral region is a region in which the pixels PXL are not provided.The peripheral region may be a region in which any image is notdisplayed.

The substrate SUB may include an insulative material such as glass,organic polymer, or quartz. The substrate SUB may be made of a materialhaving flexibility to be bendable or foldable. The substrate SUB mayhave a single-layered or multi-layered structure.

For example, the substrate SUB may include at least one of polystyrene,polyvinyl alcohol, polymethyl methacrylate, polyethersulfone,polyacrylate, polyetherimide, polyethylene naphthalate, polyethyleneterephthalate, polyphenylene sulfide, polyarylate, polyimide,polycarbonate, triacetate cellulose, and cellulose acetate propionate.However, the material constituting the substrate SUB may be variouslychanged.

The signal lines provide signals to each pixel PXL, and includes a scanline SL, a data line DL1, an emission control line EL, and a power linePL.

The scan line SL may include a first portion extending in a firstdirection DR1 and a second portion protruding from the first portion toextend in a second direction DR2 intersecting the first direction DR1. Ascan signal may be provided to the scan line SL.

The emission control line EL extends in the second direction DR2 and maybe disposed to be spaced apart from the data line DL. An operationcontrol signal may be provided to the emission control line EL.

The data line DL extends in the second direction DR2, and the emissioncontrol line EL and the data line DL are sequentially arranged along thefirst direction DR1.

The power line PL extends along the second direction DR2 and may bedisposed to be spaced apart from the data line DL. The first powersource ELVDD may be provided to the power line PL.

Each pixel PXL may include first to third blocking layers SDL1 to SDL3,first to third transistors T1 to T3, a storage capacitor Cst, a lightemitting element OLED, and a bridge pattern BRP.

The first to third blocking layers SDL1 to SDL3 may be disposed on thesubstrate SUB. The first to third blocking layers SDL1 to SDL3 may bemade of a conductive material, e.g., metal. The first to third blockinglayers SDL1 to SDL3 may be formed of a single metal, but be made of twokinds of metals, an alloy of two kinds of metals, or the like. Inaddition, the first to third blocking layers SDL1 to SDL3 may be formedin a single layer or a multi-layer. The first to third blocking layersSDL1 to SDL3 may block light incident through the back surface of thesubstrate SUB. Here, the first blocking layer SDL1 may partially overlapwith the first transistor T1 when viewed on a plane. The second blockinglayer SDL2 may partially overlap with the second transistor T2 whenviewed on a plane. In addition, the third blocking layer SDL3 maypartially overlap with the third transistor T3 when viewed on a plane.

The first transistor T1 includes a first gate electrode GE1, a firstactive pattern ACT1, a first source electrode SE1, and a first drainelectrode DE1.

The first gate electrode GE1 is connected to the scan line SL. The firstgate electrode GE1 may be provided as a portion of the scan line SL, butthe present disclosure is not limited thereto. For example, the firstgate electrode GE1 may be provided in a shape protruding from the scanline SL. In an embodiment, the first active pattern ACT1, the firstsource electrode SE1, and the first drain electrode DE1 may be formed ofa semiconductor layer that is undoped with an impurity or is doped withthe impurity. The first source electrode SE1 and the first drainelectrode DE1 may be formed of the semiconductor layer that is dopedwith the impurity, and the first active pattern ACT1 may be formed ofthe semiconductor layer that is undoped with the impurity. The firstactive pattern ACT1 corresponds to a portion overlapping with the firstgate electrode GE1. One end of the first source electrode SE1 isconnected to the first active pattern ACT1, and the other end of thefirst source electrode SE1 is connected to the bridge pattern BRPthrough a second contact hole CH2. One end of the first drain electrodeDE1 is connected to the first active pattern ACT1, and the other end ofthe first drain electrode DE1 is connected to the data line DL throughthe first contact hole CH1.

The first transistor T1 partially overlaps with the first blocking layerSDL1 when viewed on a plane. In particular, the first active patternACT1 of the first transistor T1 may completely overlap with the firstblocking layer SDL1. Therefore, when light is incident through the backsurface of the substrate SUB, the first blocking layer SDL1 can blockthe light from reaching the first active pattern ACT1 by covering thefirst active pattern ACT1.

The first blocking layer SDL1 may be connected to the first gateelectrode GE1 of the first transistor T1 through a first connection lineCNL1 and third and fourth contact holes CH3 and CH4. One side of thefirst connection line CNL1 is connected to the first gate electrode GE1through the third contact hole CH3, and the other side of the firstconnection line CNL1 is connected to the first blocking layer SDL1through the fourth contact hole CH4. Therefore, the first gate electrodeGE1 and the first blocking layer SDL1 may be electrically connected toeach other. Thus, a voltage of the same level as a voltage provided tothe first gate electrode GE1 may be applied to the first blocking layerSDL1. The first blocking layer SDL1 may be disposed between thesubstrate SUB and the semiconductor layer.

As described above, if the first blocking layer SDL1 is electricallyconnected to the first gate electrode GE1, channels may be formed on atop surface and a bottom surface of the first active pattern ACT1, thus,the storage capacitor Cst can be charged to a data voltage quicklybecause on current Ion of the first transistor T1 may be increased.

If the first blocking layer SDL1 is connected to the first sourceelectrode SE1, a parasitic capacitor may be generated between a secondgate electrode GE2 of the second transistor T2 and the first sourceelectrode SE1 by the scan signal provided to the first gate electrodeGE1. Therefore, electrical properties of the first transistor T1 may bedeteriorated.

Thus, as the first blocking layer SDL1 is electrically connected to thefirst gate electrode GE1, electrical properties of the first and secondtransistors T1 and T2 can be improved.

The second transistor T2 includes the second gate electrode GE2, asecond active pattern ACT2, a second source electrode SE2, and a seconddrain electrode DE2.

The second gate electrode GE2 is connected to the first source electrodeSE1 of the first transistor T1. The bridge pattern BRP connects betweenthe second gate electrode GE2 and the first source electrode SE1. Thebridge pattern BRP connects the second gate electrode GE2 to the firstsource electrode SE1 through the second contact hole CH2 and a fifthcontact hole CH5.

In addition, the second gate electrode GE2 extends along the seconddirection DR2 when viewed on a plane, and may be integrally providedwith a lower electrode LE of the storage capacitor Cst which will bedescribed later. That is, the second gate electrode GE2 may be providedin the same layer as the lower electrode LE.

In an embodiment, the second active pattern ACT2, the second sourceelectrode SE2, and the second drain electrode DE2 may be formed of asemiconductor layer that is undoped with an impurity or is doped withthe impurity. The second source electrode SE2 and the second drainelectrode DE2 may be formed of the semiconductor layer that is dopedwith the impurity, and the second active pattern ACT2 may be formed ofthe semiconductor layer that is undoped with the impurity. The secondactive pattern ACT2 may partially overlap with a portion of the secondgate electrode GE2 when viewed on a plane. One end of the second sourceelectrode SE2 is connected to the second active pattern ACT2, and theother end of the second source electrode SE2 is connected to an anodeelectrode AD of the light emitting element OLED through a secondconnection line CNL2 and a twelfth contact hole CH12. One end of thesecond drain electrode DE2 is connected to the second active patternACT2, and the other end of the second drain electrode DE2 is connectedto a third source electrode SE3 of the third transistor T3.

The second transistor T2 partially overlaps with the second blockinglayer SDL2 when viewed on a plane. In particular, the second activepattern ACT2 of the second transistor T2 may completely overlap with thesecond blocking layer SDL2. Therefore, when light is incident throughthe back surface of the substrate SUB, the second blocking layer SDL2can block the light from reaching the second active pattern ACT2 bycovering the second active pattern ACT2.

The second blocking layer SDL2 may be connected to the second sourceelectrode SE2 of the second transistor T through the second connectionlayer CNL2 and ninth and tenth contact holes CH9 and CH10. One side ofthe second connection line CNL2 is connected to the second sourceelectrode SE2 through the ninth contact hole CH9, and the other side ofthe second connection line CNL2 is connected to the second blockinglayer SDL2 through the tenth contact hole CH10. Therefore, the secondsource electrode SE2 and the second blocking layer SDL2 may beelectrically connected to each other. Thus, a voltage of the same levelas a voltage provided to the second source electrode SE2 can be appliedto the second blocking layer SDL2. The second blocking layer SDL2 may bea component that is first disposed on the substrate SUB, like the firstblocking layer SDL.

As described above, if the second blocking layer SDL2 is electricallyconnected to the second source electrode SE2, a swing width margin ofthe second power source ELVSS can be ensured. In this case, the drivingrange of a gate voltage applied to the second gate electrode GE2 of thesecond transistor T2 can be widened.

In the display according to the embodiment of the present disclosure,the second blocking layer SDL2 may be electrically connected to thesecond source electrode SE2, but the present disclosure is not limitedthereto. For example, the second blocking layer SDL2 may also beelectrically connected to the second gate electrode GE2.

If the second blocking layer SDL2 is electrically connected to thesecond gate electrode GE2, an on-current Ion of the second transistor T2may be increased. In this case, the capacitance of the storage capacitorCst may be increased and be stable in coupling. The second transistorT2, as shown in the drawings, may be provided in plural numbers so as toprevent leakage current, but the present disclosure is not limitedthereto. For example, one second transistor T2 may be provided, like thefirst transistor T1.

The third transistor T3 includes a third gate electrode GE3, an activepattern ACT3, the third source electrode SE3, and a third drainelectrode DE3.

In an embodiment, the third active pattern ACT3, the third sourceelectrode SE3, and the third drain electrode DE3 may be formed of asemiconductor layer that is undoped with an impurity or is doped withthe impurity. The third source electrode SE3 and the third drainelectrode DE3 may be formed of the semiconductor layer that is dopedwith the impurity, and the third active pattern ACT3 may be formed ofthe semiconductor layer that is undoped with the impurity. The thirdactive pattern ACT3 corresponds to a portion overlapping with the thirdgate electrode GE3. One end of the third source electrode SE3 isconnected to the third active pattern ACT3, and the other end of thethird source electrode SE3 is connected to the second drain electrodeDE2 of the second transistor T2. One end of the third drain electrodeDE3 is connected to the third active pattern ACT3, and the other end ofthe third drain electrode DE3 is connected to the power line PL throughan eighth contact hole CH8.

The third transistor T3 partially overlaps with the third blocking layerSDL3 when viewed on a plane. In particular, the third active patternACT3 of the third transistor T3 may completely overlap with the thirdblocking layer SDL3. Therefore, when light is incident through the backsurface of the substrate SUB, the third blocking layer SDL3 can blockthe light from reaching the third active pattern ACT3 by covering thethird active pattern ACT3.

The third blocking layer SDL3 may be connected to the third gateelectrode GE3 of the third transistor T3 through a third connection lineCNL3, a sixth contact hole CH6, and a seventh contact hole CH7. One sideof the third connection line CNL3 may be connected to the third blockinglayer SDL3 through the sixth contact hole CH6, and the other side of thethird connection line CNL3 may be connected to the third gate electrodeGE3. Therefore, the third blocking layer SDL3 and the third gateelectrode GE3 may be electrically connected to each other. Thus, avoltage of the same level as a voltage provided to the third gateelectrode GE3 may be applied to the third blocking layer SDL3. Like thefirst and second blocking layers SDL1 and SDL2, the third blocking layerSDL3 may be a component that is first disposed on the substrate SUB.

As described above, if the third blocking layer SDL3 is electricallyconnected to the third gate electrode GE3, the on-current Ion isincreased, so that electrical properties of the third transistor T3 canbe improved.

If the third blocking layer SDL3 is connected to the third sourceelectrode SE3, an initialization time may be taken longer than that whenthe third blocking layer SDL3 is connected to the third gate electrodeGE3.

Thus, as the third blocking layer SDL3 is electrically connected to thethird gate electrode GE3, electrical properties of the third transistorT3 can be improved.

The third transistor T3, as shown in the drawings, may be provided inplurality so as to prevent leakage current, but the present disclosureis not limited thereto. For example, one third transistor T3 may beprovided, like the first transistor T1.

The storage capacitor Cst includes the lower electrode LE and an upperelectrode UE. The lower electrode LE of the storage capacitor Cst may beprovided as the second gate electrode GE2 of the second transistor T2.The upper electrode UE of the storage capacitor Cst overlaps with thesecond gate electrode GE2 with a first insulating layer IL1 interposedtherebetween, and covers a majority of the second gate electrode GE2when viewed on a plane. The overlapping area of the upper electrode UEand the lower electrode LE is widened, so that the capacitance of thestorage capacitor Cst can be increased.

The light emitting element OLED may include the anode electrode AD, acathode electrode CD, and an emitting layer EML provided between theanode electrode AD and the cathode electrode CD.

The anode electrode AD is provided in a pixel region corresponding toeach pixel PXL. The anode electrode AD is connected to the upperelectrode UE of the storage capacitor Cst and the second sourceelectrode SE2 of the second transistor T2 through an eleventh contacthole CH11 and the twelfth contact hole CH12. The second connection lineCNL2 may be provided between the eleventh contact hole CH11 and thetwelfth contact hole CH12. The second connection line CNL2 may be acomponent that allows the upper electrode UE, the second sourceelectrode SE2, and the anode electrode AD to be connected to each other.

Again, a structure of the display device according to the embodiment ofthe present disclosure will be described along a stacking order withreference to FIGS. 2 to 6.

First, the first to third blocking layers SDL1 to SDL3 may be disposedon the substrate SUB. The first to third blocking layers SDL1 to SDL3may be spaced apart from each other on the substrate SUB. The first tothird blocking layers SDL1 to SDL3 may be made of a conductive material,e.g., metal. The first to third blocking layers SDL1 to SDL3 may beformed of a single metal, but be made of two kinds of metals, an alloyof two kinds of metals, or the like. In addition, the first to thirdblocking layers SDL1 to SDL3 may be formed in a single layer or amulti-layer. The first to third blocking layers SDL1 to SDL3 may blocklight incident through the back surface of the substrate SUB fromreaching the first to third active layers ACT1 to ACT3. The first tothird blocking layers SDL1 to SDL3 may be provided in various shapeswithin a limit capable of blocking the light from being incident intothe first to third transistors T1 to T3 from the back surface of thesubstrate SUB. In an embodiment, the first to third blocking layers SDL1to SDL3 may be provided in a quadrangular shape and a polygonal shapewhen viewed on a plane. However, the present disclosure is not limitedthereto, and the first to third blocking layers SDL1 to SDL3 may beprovided in various shapes including an elliptical shape, a circularshape, and the like.

Subsequently, a buffer layer BFL may be provided over the first to thirdblocking layers SDL1 to SDL3. The buffer layer BFL may be made of anorganic insulating material or an inorganic insulating material. Theinorganic insulating material may include silicon oxide or siliconnitride.

A semiconductor layer SML is provided on the buffer layer BFL. Thesemiconductor layer SML includes the first to third source electrodesSE1 to SE3, the first to third drain electrodes DE1 to DE3, and thefirst to third active patterns ACT1 to ACT3 respectively providedbetween the source electrodes SE1 to SE3 and the drain electrodes DE1 toDE3.

A gate insulating layer GI may be disposed on the substrate SUB havingthe semiconductor layer formed thereon. The gate insulating layer GI mayinclude any one insulating material selected from an inorganicinsulating material including an inorganic substance and an organicinsulating material including an organic substance.

The scan line SL, the first to third gate electrodes GE1 to GE3, and thethird connection line CNL3 may be disposed on the gate insulating layerGI.

The second gate electrode GE2 may be integrally provided with the lowerelectrode of the storage capacitor Cst. That is, an expanded portion ofthe second gate electrode GE2 may become the lower electrode LE.

The third connection line CNL3 may be integrally provided with the thirdgate electrode GE3. That is, the third connection line CNL3 may becomethe third gate electrode GE3.

The first insulating layer IL1 is disposed on the substrate SUB on thescan line SL and the like are formed. The first insulating layer IL1 maybe made of the same insulating material as the gate insulating layer GI,but the present disclosure is not limited thereto.

The upper electrode UE of the storage capacitor Cst is disposed on thefirst insulating layer IL1. The upper electrode UE overlaps with thelower electrode LE with the first insulating layer IL1 interposedtherebetween, thereby constituting the storage capacitor Cst.

A second insulating layer IL2 is disposed on the substrate SUB havingthe upper electrode UE formed thereon. The second insulating layer IL2may be made of the same insulating material as the first insulatinglayer IL1, but the present disclosure is not limited thereto.

The data line DL, the power line PL, the emission control line EL, thefirst and second connection lines CNL1 and CNL2, and the bridge patternBRP are disposed on the second insulating layer IL2.

The data line DL is connected to the first drain electrode DE1 throughthe first contact hole CH1 formed through the gate insulating layer GIand the first and second insulating layers IL1 and IL2.

The power line PL is connected to the third drain electrode DE3 throughthe eighth contact hole CH8 formed through the gate insulating layer GIand the first and second insulating layers IL1 and IL2.

The emission control line EL is connected to the third gate electrodeGE3 through the seventh contact hole CH7 formed through the first andsecond insulating layers IL1 and IL2. Also, the emission control line ELis connected to the third blocking layer SDL3 through the sixth contacthole CH6 formed through the gate insulating layer GI, the first andsecond insulating layers IL1 and IL2, and the buffer layer BFL.Therefore, the third gate electrode GE3 and the third blocking layerSDL3 may be connected to each other.

The first connection line CNL1 is connected to the first gate electrodeGE1 through the third contact hole CH3 formed through the first andsecond insulating layers IL1 and IL2. Also, the first connection lineCNL1 is connected to the first blocking layer SDL1 through the fourthcontact hole CH4 formed through the gate insulating layer GI, the firstand second insulating layers IL1 and IL2, and the buffer layer BFL.Therefore, the first gate electrode GE1 and the first blocking layerSDL1 may be connected to each other.

The second connection line CNL2 is connected to the second sourceelectrode SE2 through the ninth contact hole CH9 formed through the gateinsulating layer GI and the first and second insulating layers IL1 andIL2. Also, the second connection line CNL2 is connected to the secondblocking layer SDL2 through the tenth contact hole CH10 formed throughthe gate insulating layer GI, the first and second insulating layers IL1and IL2, and the buffer layer BFL. Also, the second connection line CNL2is connected to the upper electrode UE through the eleventh contact holeCH11 formed through the second insulating layer IL2. In addition, thesecond connection line CNL2 is connected to the anode electrode ADthrough the twelfth contact hole CH12. Therefore, the second sourceelectrode SE2 may be connected to each of the second blocking layer SDL2and the anode electrode AD. In addition, the upper electrode UE and theanode electrode AD may be connected to each other.

The bridge pattern BRP is connected to the first source electrode SE1through the second contact hole CH2 formed through the gate insulatinglayer GI and the first and second insulating layers IL1 and IL2. Also,the bridge pattern BRP is connected to the second gate electrode GE2through the fifth contact hole CH5 formed through the first and secondinsulating layers IL1 and IL2. Therefore, the first source electrode SE1and the second gate electrode GE2 may be connected to each other.

A protective layer PSV is disposed on the substrate SUB on which thedata line DL and the like are formed. The anode electrode AD is disposedon the protective layer PSV.

The anode electrode AD may be connected to the second connection lineCNL2 through the twelfth contact hole CH12 formed through the protectivelayer PSV. Since the second connection line CNL2 is connected to thesecond source electrode SE2 through the ninth contact hole CH9 and isconnected to the upper electrode UE through the tenth contact hole CH10,the anode electrode AD may be finally connected to the second sourceelectrode SE2 and the upper electrode UE.

A pixel defining layer PDL that defines a pixel region to correspond toeach pixel PXL may be provided on the substrate SUB having the anodeelectrode AD formed thereon. The pixel defining layer PDL exposes a topsurface of the anode electrode AD, and may protrude from the substrateSUB along the circumference of the pixel PXL.

The emitting layer EML may be provide in the pixel region surrounded bythe pixel defining layer PDL, and the cathode electrode CD may beprovided on the emitting layer EML.

An encapsulation layer SLM that covers the cathode electrode CD may beprovided over the cathode electrode CD.

According to the above-described embodiment, in each pixel PXL, thefirst to third blocking layers SDL1 to SDL3 partially overlapping withthe respective first to third transistors T1 to T3 are disposed betweenthe substrate SUB and the gate insulating layer GI, so that it ispossible to prevent light incident through the back surface of thesubstrate SUB from reaching the first to third transistors T1 to T3.Accordingly, it is possible to prevent properties of the first to thirdtransistors T1 to T3 from being deteriorated, thereby implementing ahigh-resolution display device.

Further, according to the above-described embodiment, as the secondblocking layer SDL2 is connected to the second source electrode SE2 ofthe second transistor T2, the first transistor T1 is drain sync-operatedduring the first period a (reset period or initialization period), sothat the initialization time can be reduced. In addition, the swingwidth margin of the second power source ELVSS is ensured, so that thedriving range of the gate voltage applied to the second gate electrodeGE2 can be widened.

FIGS. 7A to 7E are layout diagrams schematically illustrating componentsof the pixel shown in FIG. 5 for each layer.

First, referring to FIGS. 5 and 7A, first to third blocking layers SDL1to SDL3 are provided on the substrate (see SUB of FIG. 6).

Referring to FIGS. 5 and 7B, a semiconductor layer SML partiallyoverlapping with each of the first to third blocking layers SDL1 to SDL3is provided with the buffer layer (see BFL of FIG. 6) interposedtherebetween. The semiconductor layer SML may include first to thirdsource electrodes SE1 to SE3, first to third drain electrodes DE1 toDE3, and first to third active patterns ACT1 to ACT3. The first to thirdsource electrodes SE1 to SE3, the first to third drain electrodes DE1 toDE3, and the first to third active patterns ACT1 to ACT3 may be providedin the same layer and be formed through the same process.

Referring to FIGS. 5 to 7C, a scan line SL, a lower electrode LE, and athird connection line CNL3 are provided on the semiconductor layer (seeSML of FIG. 7B) with the gate insulating layer (see GI of FIG. 6)interposed therebetween. The scan line SL, the lower electrode LE, andthe third connection line CNL3 may be provided in the same layer and beformed through the same process.

A first gate electrode GE1 may be connected to the scan line SL. Asecond gate electrode GE2 may be connected to the lower electrode LE. Athird gate electrode GE3 may be connected to the third connection lineCNL3.

Referring to FIGS. 5 to 7D, an upper electrode UE is provided on thelower electrode LE with the first insulating layer (see IL1 of FIG. 6)interposed therebetween. The upper electrode UE may overlap with thelower electrode LE with the first insulating layer IL1 interposedtherebetween, thereby constituting a storage capacitor Cst.

Referring to FIGS. 5 to 7E, a data line DL, a power line PL, an emissioncontrol line EL, first and second connection lines CNL1 and CNL2, and abridge pattern BRP are provided on the upper electrode UE with thesecond insulating layer (see IL2 of FIG. 6) interposed therebetween.

The data line DL is connected to the first drain electrode DE1 through afirst contact hole CH1. The power line PL is connected to the thirddrain electrode DE3 through an eighth contact hole CH8. The emissioncontrol line EL is connected to the third connection line CNL3 through aseventh contact hole CH7, and is connected to the third blocking layerSDL3 through a sixth contact hole CH6.

The first connection line CNL1 connects the first gate electrode GE1 andthe first blocking layer SDL1 through third and fourth contact holes CH3and CH4.

The second connection line CNL2 connects the second source electrodeSE2, the upper electrode UE, and the anode electrode (see AD of FIG. 5)through a ninth contact hole CH9, an eleventh contact hole CH11, and atwelfth contact hole CH12. Also, the second connection line CNL2connects the second blocking layer SDL2 and the second source electrodethrough a tenth contact hole CH10.

The bridge pattern BRP is connected to the first source electrode SE1through a second contact hole CH2, and is connected to the second gateelectrode GE2 through a fifth contact hole CH5. Therefore, the firstsource electrode SE1 and the second gate electrode GE2 may be connectedto each other.

FIG. 8 is a plan view implementing the pixel of FIG. 2 according toanother embodiment of the inventive concept. FIG. 9 is a sectional viewtaken along line II-IP of FIG. 8. In a display device including thepixel implemented as another embodiment of the present disclosure,differences from the display device according to the above-describedembodiment will be mainly described to avoid redundancy. Portions notparticularly described in the another embodiment of the presentdisclosure follow those of the display device according to theabove-described embodiment. In addition, identical reference numeralsrefer to identical components, and similar reference numerals refer tosimilar components.

Referring to FIGS. 2, 8, and 9, the display device according to theanother embodiment of the present disclosure includes a substrate SUB,signal lines, and pixels PXL.

The signal lines provide signals to each pixel, and includes a scan lineSL, a data line DL, an emission control line EL, and a power line PL.

Each pixel PXL includes first to third transistors T1 to T3, a storagecapacitor Cst, a light emitting element OLED, a bridge pattern BRP,first to third connection lines CNL1 to CNL3, and first to thirdblocking layers SDL1 to SDL3.

The first to third blocking layers SDL1 to SDL3 are disposed on thesubstrate SUB. The first blocking layer SDL1 may partially overlap witha first active pattern ACT1 of the first transistor T1 when viewed on aplane. The second blocking layer SDL2 may partially overlap with asecond active pattern ACT2 of the second transistor T2 when viewed on aplane. The third blocking layer SDL3 may partially overlap with a thirdactive pattern ACT3 of the third transistor T3 when viewed on a plane.As the first to third blocking layers SDL1 to SDL3 completely cover thefirst to third active patterns ACT1 to ACT3, respectively, it ispossible to block light incident through the back surface of thesubstrate SUB from reaching the first to third active patterns ACT1 toACT3.

The first transistor T1 includes a first gate electrode GE1, the firstactive pattern ACT1, a first source electrode SE1, and a first drainelectrode DE1. The first gate electrode GE1 may be connected to thefirst blocking layer SDL1 through the first connection line CNL1.

The second transistor T2 includes a second gate electrode GE2, thesecond active pattern ACT2, a second source electrode SE2, and a seconddrain electrode DE2. The second source electrode SE2 may be connected tothe second blocking layer SDL2 through the second connection line CNL2.

The third transistor T3 includes a third gate electrode GE3, the thirdactive pattern ACT3, a third source electrode SE3, and a third drainelectrode DE3. The third gate electrode GE3 may be connected to thethird blocking layer SDL3 through the emission control line EL and thethird connection line CNL3.

The storage capacitor Cst includes a lower electrode LE and an upperelectrode UE. The lower electrode LE of the storage capacitor Cst may beprovided as the second blocking layer SDL2. The upper electrode UE ofthe storage capacitor Cst may be provided as the second gate electrodeGE2 of the second transistor T2. The overlapping area of the upperelectrode UE and the lower electrode LE is widened, so that thecapacitance of the storage capacitor Cst can be increased.

The light emitting element OLED may include an anode electrode AD, acathode electrode CD, and an emitting layer EML disposed between theanode electrode AD and the cathode electrode CD.

Again, a structure of the display device according to the anotherembodiment of the present disclosure will be described along a stackingorder with reference to FIGS. 2, 8, and 9.

First, the first to third blocking layers SDL1 to SDL3 may be disposedon the substrate SUB. The second blocking layer SDL2 may be integrallyprovided with the lower electrode LE of the storage capacitor Cst. Thatis, an expanded portion of the second blocking layer SDL2 may become thelower electrode LE.

Subsequently, a buffer layer BFL may be provided over the first to thirdblocking layers SDL1 to SDL3 and the lower electrode LE.

A semiconductor layer may be disposed on the buffer layer BFL. Thesemiconductor layer includes the first to third source electrodes SE1 toSE3, the first to third drain electrodes DE1 to DE3, and the first tothird active patterns ACT1 to ACT3 respectively provided between thesource electrodes SE1 to SE3 and the drain electrode DE1 to DE3.

A gate insulating layer GI may be disposed on the substrate SUB havingthe semiconductor layer formed thereon.

The scan line SL, the first to third gate electrodes GE1 to GE3, and thethird connection line CNL3 may be disposed on the gate insulating layerGI. The second gate electrode GE2 may be integrally provided with theupper electrode UE of the storage capacitor Cst. That is, an expandedportion of the second gate electrode GE2 may become the upper electrodeUE.

The first gate electrode GE1 may be integrally provided with the scanline SL and be provided on the first active pattern ACT1, to be used asan anti-doping layer that allows the first active pattern ACT1 not to bedoped with an impurity. Accordingly, the first gate electrode GE1 candefine a channel region of the first active pattern ACT1.

The second gate electrode GE2 may be used as the upper electrode UE ofthe storage capacitor Cst and be disposed on the second active patternACT2, to be used as an anti-doping layer that allows the second activepattern ACT2 not to be doped with the impurity. Accordingly, the secondgate electrode GE2 can define a channel region of the second activepattern ACT2.

The upper electrode UE may overlap with the lower electrode LE with thegate insulating layer GI and the buffer layer BFL interposedtherebetween to constitute the storage capacitor Cst.

The third gate electrode GE3 may be used as the third connection lineCNL3 and be provided on the third active layer ACT3, to be used as ananti-doping layer that allows the third active pattern ACT3 not to bedoped with the impurity. Accordingly, the third gate electrode GE3 candefine a channel region of the third active pattern ACT3.

The third connection line CNL3 may be integrally provided with the thirdgate electrode GE3. That is, the third connection line CNL3 may becomethe third gate electrode GE3.

First and second insulating layers IL1 and IL2 may be disposed on thesubstrate SUB on which the scan line SL, the first to third gateelectrodes GE1 to GE3, the third connection line CNL3, and the upperelectrode UE are formed.

The data line DL, the power line PL, the emission control line EL, thefirst and second connection lines CNL1 and CNL2, and the bridge patternBRP may be disposed on the second insulating layer IL2.

A protective layer PSV may be disposed on the substrate SUB on the dataline DL and the like are formed.

The anode electrode AD may be disposed on the protective layer PSV. Theanode electrode AD may be connected to the second connection line CNL2through a twelfth contact hole CH12 formed through the protective layerPSV. The anode electrode AD may be finally connected to the secondsource electrode SE2 and the upper electrode UE.

A pixel defining layer PDL may be disposed on the substrate SUB havingthe anode electrode AD formed thereon, the emitting layer EML may beprovided in a pixel region surrounded by the pixel defining layer PDL,and the cathode electrode CD may be provided on the emitting layer EML.

An encapsulation layer SML that covers the cathode electrode CD may beprovided over the cathode electrode CD.

According to the above-described embodiment, in each pixel PXL, thefirst to third blocking layers SDL1 to SDL3 partially overlapping withthe respective first to third transistors T1 to T3 are disposed betweenthe substrate SUB and the buffer layer BFL, so that it is possible toprevent light incident through the back surface of the substrate SUBfrom reaching the first to third transistors T1 to T3.

Further, according to the above-described embodiment, the secondblocking layer SDL2 is used as the lower electrode LE of the storagecapacitor Cst, and the second gate electrode GE2 is used as the upperelectrode UE of the storage capacitor Cst, so that some of the layersprovided on the substrate SUB can be omitted. Accordingly, themanufacturing process of the display device can be simplified, and themanufacturing cost of the display device can be reduced.

FIGS. 10A to 10D are layout diagrams schematically illustratingcomponents of the pixel shown in FIG. 8 for each layer.

First, referring to FIGS. 8 and 10A, first to third blocking layers SDL1to SDL3 are disposed on the substrate (see SUB of FIG. 9). Here, a lowerelectrode LE of a storage capacitor Cst may be provided with the secondblocking layer SDL2.

Referring to FIGS. 8 and 10B, a semiconductor layer SML partiallyoverlapping with the respective first to third blocking layers SDL1 toSDL3 is provided on the buffer layer (see BFL of FIG. 9). Thesemiconductor layer SML may include first to third source electrodes SE1to SE3, first to third drain electrodes DE1 to DE3, and first to thirdactive patterns ACT1 to ACT3.

Referring to FIGS. 8 and 10C, a scan line SL, a third connection lineCNL3, and a second gate electrode GE2 are disposed on the semiconductorlayer (see SML of FIG. 10) on the gate insulating layer (see GI of FIG.9).

A first gate electrode GE1 may be connected to the scan line SL. A thirdgate electrode GE3 may be connected to the third connection line CNL3.The second gate electrode GE2 may be integrally provided with an upperelectrode UE of the storage capacitor Cst.

Referring to FIGS. 8 and 10D, a data line DL, a power line PL, anemission control line EL, first and second connection lines CNL1 andCNL2, and a bridge pattern BRP are disposed on the scan line SL, thethird connection line CNL3, and the first to third gate electrodes GE1to GE3 with the first and second insulating layers (see IL1 and IL2 ofFIG. 9) interposed therebetween.

The data line DL is connected to the first drain electrode DE1 through afirst contact hole CH1. The power line PL is connected to the thirddrain electrode DE3 through an eighth contact hole CH8. The emissioncontrol line EL is connected to the third gate electrode GE3 integrallyprovided with the third connection line CNL3 through a seventh contacthole CH7, and is connected to the third blocking layer SDL3 through asixth contact hole CH6. Therefore, the third gate electrode GE3 and thethird blocking layer SDL3 may be connected to each other.

The first connection line CNL1 is connected to the first gate electrodeGE1 through a third contact hole CH3, and is connected to the firstblocking layer SDL1 through a fourth contact hole CH4. Therefore, thefirst gate electrode GE1 and the first blocking layer SDL1 may beconnected to each other.

The second connection line CNL2 is connected to the second sourceelectrode SE2 through a ninth contact hole CH9, is connected to theupper electrode UE through an eleventh contact hole CH11, and isconnected to the anode electrode (see AD of FIG. 9) through a twelfthcontact hole CH12. Also, the second connection line CNL2 is connected tothe second blocking layer SDL2 through a tenth contact hole CH10.Therefore, the second source electrode SE2 and the second blocking layerSDL2 may be connected to each other.

The bridge pattern BRP is connected to the first source electrode SE1through a second contact hole CH2, and is connected to the second gateelectrode GE2 through a fifth contact hole CH5. Therefore, the firstsource electrode SE1 and the second gate electrode GE2 may be connectedto each other.

The display device according to the present disclosure can be employedin various electronic devices. For example, the display device isapplicable to televisions, notebook computers, cellular phones, smartphones, smart pads, PMPs, PDAs, navigations, various wearable devicessuch as smart watches, and the like.

According to the present disclosure, it is possible to provide a displaydevice which implements high resolution.

Example embodiments have been disclosed herein, and although specificterms are employed, they are used and are to be interpreted in a genericand descriptive sense only and not for purpose of limitation. In someinstances, as would be apparent to one of ordinary skill in the art asof the filing of the present application, features, characteristics,and/or elements described in connection with a particular embodiment maybe used singly or in combination with features, characteristics, and/orelements described in connection with other embodiments unless otherwisespecifically indicated. Accordingly, it will be understood by those ofskill in the art that various changes in form and details may be madewithout departing from the spirit and scope of the present disclosure asset forth in the following claims.

What is claimed is:
 1. A display device having a pixel region and aperipheral region, the display device comprising: a plurality of pixelsprovided in the pixel region of a substrate; a scan line and a dataline, connected to each of the plurality of pixels; a transistorprovided in the pixel region, the transistor including a firsttransistor connected to the scan line and the data line and a secondtransistor connected to the first transistor; a light emitting elementconnected to the transistor; a first blocking layer disposed between thesubstrate and the first transistor, the first blocking layer beingelectrically connected to the first transistor; and a second blockinglayer disposed between the substrate and the second transistor, thesecond blocking layer being electrically connected to the secondtransistor, wherein the first blocking layer is connected to a gateelectrode of the first transistor, and the second blocking layer isconnected to any one of source and drain electrodes of the secondtransistor.
 2. The display device of claim 1, wherein, when viewed on aplane, the first blocking layer overlaps with a portion of the firsttransistor, and the second blocking layer overlaps with a portion of thesecond transistor.
 3. The display device of claim 2, wherein the firstblocking layer and the second blocking layer are provided on the samelayer.
 4. The display device of claim 2, wherein the second transistorincludes: an active pattern disposed on the substrate; a gate electrodedisposed on the active pattern; and source and drain electrodes, eachconnected to the active pattern, wherein the source electrode isconnected to the second blocking layer.
 5. The display device of claim4, comprising: a buffer layer disposed between the second blocking layerand the active pattern; and a gate insulating layer, a first insulatinglayer, and a second insulating layer, sequentially disposed on thebuffer layer.
 6. The display device of claim 5, comprising: a lowerelectrode disposed on the gate insulating layer; and an upper electrodedisposed on the first insulating layer, wherein the lower electrode andthe upper electrode constitute a storage capacitor with the firstinsulating layer interposed therebetween.
 7. The display device of claim6, wherein the lower electrode is integrally provided with the gateelectrode of the second transistor.
 8. The display device of claim 5,comprising: a lower electrode disposed between the substrate and thebuffer layer; and an upper electrode disposed on the gate insulatinglayer, wherein the lower electrode and the upper electrode constitute astorage capacitor with the buffer layer and the gate insulating layerinterposed therebetween.
 9. The display device of claim 8, wherein thesecond blocking layer is integrally provided with the lower electrode.10. The display device of claim 5, further comprising: an emissioncontrol line disposed on the second insulating layer; a third transistorconnected to the emission control line and the second transistor; and athird blocking layer connected to the third transistor.
 11. The displaydevice of claim 10, wherein, when viewed on a plane, the third blockinglayer overlaps with a portion of the third transistor.
 12. The displaydevice of claim 11, wherein the third transistor includes: an activepattern disposed on the substrate; a gate electrode disposed on theactive pattern; and source and drain electrodes, each connected to theactive pattern, wherein the gate electrode is connected to the thirdblocking layer.
 13. The display device of claim 12, wherein the thirdblocking layer is a light blocking layer that blocks light incidentthrough one surface of the substrate, on which the active pattern of thethird transistor is not provided.
 14. The display device of claim 13,wherein the third blocking layer is provided on the same layer as thefirst and second blocking layers.
 15. The display device of claim 10,wherein the emission control line is provided on the same layer as thedata line.
 16. The display device of claim 4, wherein the secondblocking layer is a light blocking layer that blocks light incidentthrough one surface of the substrate, on which the active pattern of thesecond transistor is not provided.
 17. The display device of claim 2,wherein the first transistor includes: an active pattern disposed on thesubstrate; a gate electrode disposed on the active pattern; and sourceand drain electrodes, each connected to the active pattern, wherein thefirst blocking layer is a light blocking layer that blocks lightincident through one surface of the substrate, on which the activepattern of the first transistor is not provided.
 18. A display devicecomprising: a first transistor connected to a data line and a scan lineto supply a data signal to a first node; a storage capacitor having oneelectrode connected to the first node and the other electrode connectedto a second node; a light emitting element having one electrodeconnected to the second node and the other electrode connected to asecond power source; a second transistor supplying a currentcorresponding to a voltage applied to the first node from a first powersource to the second power source via the light emitting element; athird transistor connected to the second transistor and an emissioncontrol line; and first to third blocking layers respectively providedunder active patterns of the first to third transistors, the first tothird blocking layers each being connected to a correspondingtransistor, wherein at least one of the first to third blocking layersis connected to a source electrode of the second transistor, and theother of the first to third blocking layers is connected to a gateelectrode of a corresponding transistor.
 19. The display device of claim18, wherein the second blocking layer is connected to the sourceelectrode of the second electrode, the first blocking layer is connectedto a gate electrode of the first transistor, and the third blockinglayer is connected to a gate electrode of the third transistor.
 20. Thedisplay device of claim 18, wherein, when viewed on a plane, the firstblocking layer overlaps with a portion of the first transistor, thesecond blocking layer overlaps with a portion of the second transistor,and the third blocking layer overlaps with a portion of the thirdtransistor.